EP2199659A1 - Optical module for automobile designed to provide a cut-off beam and main beam - Google Patents

Abstract

The module has a light source e.g. halogen lamp, constituted of a light transmitter (2) and another light transmitter shifted in a direction of an optical axis. Top and bottom concave paraboloid reflectors (R1, R2) are connected by a continuous transition zone (6). The reflectors have complex surfaces with sectors that are in prolongation of one another, such as a set of junctions between the sectors for the top reflector is in prolongation with junctions of the bottom reflector, where passage of one of the sectors to the near sector is ensured by a connection fillet removing sharp angles. The optical module is made of pressed sheet metal and injected thermosetting plastic material.

Description

• une source lumineuse constituée par au moins deux émetteurs de lumière décalés suivant la direction de l'axe optique, un premier émetteur étant associé à une coupelle d'occultation pour donner le faisceau à coupure, et un deuxième émetteur, situé en arrière du premier, émettant librement tout autour de lui pour donner le faisceau sans coupure,
• un premier réflecteur concave de type paraboloïde, qui reçoit le faisceau issu du premier émetteur pour donner le faisceau à coupure,
• un deuxième réflecteur concave, de type paraboloïde, situé en partie inférieure qui, avec le premier réflecteur, fournit le faisceau sans coupure à partir du deuxième émetteur,

les réflecteurs étant répartis de part et d'autre de deux plans axiaux , notamment inclinés sous le plan horizontal passant par l'axe optique, chaque réflecteur présentant une surface complexe avec des secteurs successifs s'étendant essentiellement dans la direction verticale.The invention relates to a motor vehicle optical module, intended to provide a cut-off beam and an unbroken beam, admitting an optical axis, of the kind comprising:

• a light source constituted by at least two light emitters shifted in the direction of the optical axis, a first emitter being associated with an occultation cup to give the cut-off beam, and a second emitter, located behind the first, emitting freely all around him to give the beam without cutoff,
• a first paraboloid-type concave reflector, which receives the beam from the first emitter to give the cut-off beam,
• a second concave reflector, of paraboloid type, located in the lower part which, with the first reflector, provides the unbroken beam from the second emitter,

the reflectors being distributed on both sides of two axial planes, in particular inclined under the horizontal plane passing through the optical axis, each reflector having a complex surface with successive sectors extending essentially in the vertical direction.

An optical module comprises a lighting unit comprising at least one reflector associated with at least one light source and capable of emitting one or more light beams. It may be a stand-alone unit, or a unit intended to be integrated into a car projector.

Generally, the light source is constituted by a lamp with two filaments, each filament constituting a light emitter.

Such an optical module is shown, in particular, by FR 2,760,070 .

Optical modules of this kind, known to date, have reflectors offset in the direction of the optical axis as shown in FIG. Figure 2 attached drawings. The lower reflector R'2 is further back than the upper reflector so that a step M, creating a discontinuity in the surface, is formed when passing from one optical module to another. This step M has no optical function, and may correspond to an empty space at least partially, mechanical connection areas that can be provided between the two reflectors.

Despite the discontinuity due to the step M, the set of both reflectors can be molded from plastic then aluminized to obtain the reflective surfaces. But such a manufacturing process is relatively expensive.

The object of the invention is, above all, to propose an automotive optical module of the kind defined above which can be mass-produced at low cost, in particular by stamping sheet metal, or by injecting thermosetting plastics material, without causing punctured zones. or exploded.

It is known from the patent application FR 2 782 149 a motor vehicle headlamp having a bi-filament lamp.

It is known from the patent application EP 875 715 a reflector for a motor vehicle headlamp.

• les deux réflecteurs sont prévus pour être raccordés par une zone de transition continue,
• les secteurs des surfaces complexes des deux réflecteurs sont dans le prolongement les uns des autres,
• et le passage d'un secteur au secteur voisin est assuré par un congé de raccordement supprimant les angles vifs.

According to the invention, an automotive optical module of the kind defined above is characterized in that:

• the two reflectors are designed to be connected by a continuous transition zone,
• the sectors of the complex surfaces of the two reflectors are in the extension of each other,
• and the passage of a sector to the neighboring sector is provided by a connection leave removing sharp angles.

The set of two reflectors thus has a relatively continuous surface.

The set of two reflectors forms a single surface in which abrupt breaks in slope are eliminated, which allows this assembly by stamping sheet metal, or by injection of thermosetting material. The disappearance of the breaks of slope and the step located between the two reflectors contributes to largely remove the varnish dripping, during the deposition of varnish, once the molded part, by injection for example, or obtained by stamping.

Generally, the focal length of the lower reflector is adapted to that of the upper reflector so that the axial offset between the two reflectors is low.

The continuous surface of the transition zone between the upper reflector and the lower reflector is defined so as to recover the luminous flux for the road beam, preferably facing downwards in order to avoid glare. In no case does the surface of this transition zone intervene in the crossing beam, at break. This transition zone is defined with polynomial curves (known in English as the "spline"), and tangents so that the continuity of the surfaces is ensured by tangency between the upper reflector for the code and the lower reflector for the road.

Advantageously, the connection fillet between two neighboring sectors of complex surface is provided in such a way that any light beam reaching this connection fillet is reflected to pass below the limit corresponding to the cutoff of the code beam. To achieve this, we can make an evolutionary connection fillet, including the different fillet radius between the upper and lower reflectors.

According to the invention, the up and down reflectors are advantageously joined.

According to the invention, preferably, a plurality of junctions between sectors for the top reflector are coherent, namely in the extension, with junctions of the reflector of the bottom.

The reflectors of the top and the bottom meet advantageously by a continuity of tangency.

The invention also relates to an automotive projector incorporating at least one optical module as defined above.

• Fig. 1 est une vue schématique de face d'un module optique selon l'invention.
• Fig.2 est une section verticale suivant la ligne II-II du module optique, avec représentation schématique en tirets d'un second réflecteur selon la technique antérieure, et
• Fig.3 est une section horizontale partielle, à plus grande échelle, suivant la ligne III - III de Fig.1.

The invention consists, apart from the arrangements set out above, in a number of other arrangements which will be more explicitly discussed below with respect to an embodiment described with reference to the accompanying drawings, but which is in no way limiting. On these drawings:

• Fig. 1 is a schematic front view of an optical module according to the invention.
• Fig.2 is a vertical section along line II-II of the optical module, with schematic dashed representation of a second reflector according to the prior art, and
• Fig.3 is a partial horizontal section, on a larger scale, along line III - III of Fig.1 .

In the description and claims, the terms "front" and "back" are to be understood in the direction of projection of the light beam coming out of the optical module forward.

Referring to the drawings, there can be seen a light optical module P of a motor vehicle intended to provide a cut beam, or code beam, and an unbroken beam, or beam route. This optical module P has an optical axis Y ( Fig.2 ), and has a central opening O for the establishment of a light source S constituted by at least one lamp 1 with two filaments 2, 3 offset along the Y axis. A lamp 1 of this type is known as H4. The first filament 2 is located in front of the second filament 3 in the direction of projection of the light. The first filament 2 may be coaxial with the Y axis while the second filament 3 is located slightly lower than the Y axis.

The first filament 2 is associated with an occultation cup 4 located below the filament 2 and having a cylindrical surface of axis adjacent or coincident with the Y axis and with an angular extent of approximately 160 °, distributed from and of other of the vertical plane passing by the axis Y according to the form of cutoff to obtain. The first filament, associated with the cup 4, gives the cut beam or code beam. The second filament 3 freely emits all around it to give the beam unbroken.

• un premier réflecteur R1 concave de type paraboloïde, à surface complexe pour engendrer un faisceau à coupure à partir de la lumière émise par le premier filament 2,
• et un deuxième réflecteur R2 concave de type paraboloïde, à surface complexe pour coopérer avec le seul second filament 3 afin de former une partie du faisceau au-dessus du faisceau à coupure et d'engendrer un maximum de lumière selon l'axe optique.

The optical module comprises, behind a mirror not shown:

• a first paraboloid-type concave reflector R1 with a complex surface for generating a cut-off beam from the light emitted by the first filament 2,
• and a second paraboloid-type concave R2 reflector with a complex surface to cooperate with only the second filament 3 to form part of the beam above the cut-off beam and to generate a maximum of light along the optical axis.

The two reflectors R1, R2 comprise, laterally juxtaposed, several smooth reflecting sectors ZLh1, ... ZLhn with a substantially vertical orientation in the central region of the reflector, and reflective zones Zsh in the lateral regions. Each of these sectors or zones is able to spread the light horizontally.

The first reflector R1 extends over two axial planes P1, P2, that is to say passing through the optical axis, inclined under the horizontal plane of an angle θ1, θ2, these two angles being slightly different. The second reflector R2 extends below the planes P1, P2.

According to a known state of the art, the optical module included a second reflector R'2 ( Fig.2 ) shifted rearwardly with respect to the first reflector, with the presence of the step M creating a discontinuity of the reflecting surface. The upper and lower reflectors of the state of the art being made independently of each other, the substantially vertical sectors of the complex surfaces were made on each reflector, without taking into account the other reflector, often with an offset transverse. In addition, in a first reflector R'1 ( Fig.3 ) according to the state of the art, the passage of a complex surface area ZL1h '(see Fig.3 ) to a sector neighbor ZL2h 'was made with a break of slope along a line 5 corresponding to an edge.

According to the invention, the two reflectors R1 and R2 are provided with focal lengths adapted so that these two reflectors can be connected by a continuous transition zone 6 extending on either side of the planes P1, P2. The transition zone 6 has an angular extent ΔP1, ΔP2, of about ten degrees with a vertex located on the optical axis.

The first filament 2 is essentially located in front of the F1 focus ( Fig.2 ) of the first reflector R1. The second filament 3 is located such that the focus F2 of the second reflector R2 is substantially at the middle of said filament. It should be noted that, preferably, the focus F2 is located along the length of the filament. In this example, it is located towards its center, but it can also be located elsewhere on the length of the filament.

The two reflectors R1, R2 comprise a plurality of smooth reflecting surfaces forming sectors ZLhn and ZLbn, and striated Zsh, Zsb juxtaposed laterally to each other.

The sectors ZLb1 ... ZLbn of the complex surface of the second reflector R2 are in the extension of the sectors ZLh1 ... ZLhn of the complex surface of the upper reflector R1. The lines such as 7, 8a, 8b separating two sectors are continuous from the reflector R1 to the reflector R2.

As illustrated on Fig.3 , the passage of a sector ZLh1 to a sector following ZLh2 is provided by a fillet 8 avoiding a slope break, and allowing a realization by sheet metal stamping. The fillet 8 is between border lines 8a, 8b delimiting a substantially vertical continuous transition band Δ (Zn) between two sectors. The bands ΔZn are equivalent to a fillet or a progressive surface, having a starting profile and an arrival profile as an evolutionary streak.

According to the example of Fig.3 , the sectors ZLh1, ZLh2 of the upper reflector R1 are convex forward to spread the light, and the fillet 8 is concave forward. The fillet fillet 8 is provided such that any radius reaching this fillet is reflected back to the limit corresponding to the cut of the code beam.

• un rayon lumineux réfléchi par le réflecteur R1 arrive sur le un écran situé à distance (à 25 mètres) du réflecteur et orthogonal à l'axe optique) suivant une direction équivalente, ou selon un angle inférieur à celui du rayon limite de la coupure, pour les rayons provenant du premier filament 2 pourvu de la coupelle 4 ;
• un rayon réfléchi dans les zones ΔP1 ou ΔP2 de la transition 6 arrive sur l'écran selon une direction équivalente ou sous un angle inférieur au rayon limite de la coupure obtenue avec le premier filament 2 ;
• un rayon provenant du deuxième filament 3 pour le faisceau sans coupure, réfléchi dans les zones ΔP1, ΔP2 arrive de façon avantageuse sur I' écran pour former un faisceau sans coupure ;
• un rayon réfléchi dans les zones de transition ΔZn du réflecteur R1 arrive sur l'écran suivant une direction équivalente ou sous un angle inférieur au rayon limite de la coupure obtenue avec le premier filament.

According to the invention, the ruptures of slope, ridges and vertical offset between the two reflectors R1, R2, corresponding to the two filaments of the source, are replaced by a surface defined as follows:

• a light beam reflected by the reflector R1 arrives on a screen located at a distance (25 meters) from the reflector and orthogonal to the axis optical) in an equivalent direction, or at an angle less than that of the limit radius of the cut, for the rays coming from the first filament 2 provided with the cup 4;
• a ray reflected in the zones ΔP1 or ΔP2 of the transition 6 arrives on the screen in a direction equivalent to or at an angle less than the limit radius of the cut obtained with the first filament 2;
• a ray coming from the second filament 3 for the unbroken beam, reflected in the zones ΔP1, ΔP2 advantageously arrives on the screen to form an unbroken beam;
• a ray reflected in the transition zones ΔZn of the reflector R1 arrives on the screen in a direction equivalent to or at an angle less than the limit radius of the cut obtained with the first filament.

Sure Fig.2 several light rays have been drawn for illustrative purposes. A radius i1, from the focus F1 of the upper reflector R1 is reflected by the latter, along a radius r1 parallel to the horizontal Y axis. A radius i2 from the middle of the filament 2 is reflected by R1 along a descending radius r2.

A ray i3, from the focus F2 of the lower reflector R2 is reflected by the latter, along a radius r3 parallel to the horizontal axis Y. A radius i4 from the middle of the filament 3 is reflected by R2 at a rising radius r4.

A ray i5, coming from the middle of the filament 3 and falling on the transition zone 6, is reflected along a ray r5 that is descending (or at most parallel to the optical axis).

According to the invention, the surface of all the two reflectors R1, R2 is continuous, which generates the possibility of stamping a sheet to achieve this surface, without risk of tearing the sheet. Stamping makes it possible to produce large series at low cost.

This continuous surface can also be obtained by molding, in particular by injection of thermosetting plastic material.

Depending on the focal length chosen for the reflectors R1, R2, the normal of the transition zone 6, or intermediate surface, is retouched so as not to create dazzle of a driver coming in the opposite direction.

The focal lengths of the reflectors R1, R2 are adjusted relative to each other to facilitate the realization of the transition surface 6, and for this surface to bring the reflected rays down to improve the illumination in the central part. beam.

The two reflectors are preferably symmetrical with respect to a vertical plane passing through the optical axis so that they can be mounted to the right or left of the vehicle. In addition, this symmetrical shape facilitates stamping.

The continuous transition zone 6 is defined so as to recover light flux and to install the images in place for the road beam.

An optical module with a diameter of 170mm and a focal length of 26.5mm offers the possibility of making a beam with a H4 type lamp having correct values, obtained with a continuous surface over the entire reflector.

With this type of surface, in the case where the reflector is obtained by injection of thermosetting plastic material, a large part of the varnish drifts due to breaks in the slope and the step between the code part and the road part will disappear thanks to the continuity of the surface.

Although the description was made with a lamp with two filaments 2, 3 constituting the light emitters, the invention applies to any type of optical module comprising at least two offset light emitters (any type of source whose lamps halogen filaments as in the example, or even light emitting diodes).

Claims (10)

Optical module for a motor vehicle, designed to give a cut-off beam and an unbroken beam, this optical module admitting an optical axis and comprising: a light source constituted by at least two light emitters shifted in the direction of the optical axis, a first emitter being associated with an occultation cup to give the cut-off beam, and a second emitter, located behind the first emitter; , emitting freely all around him to give the beam without cutoff, a first paraboloid-type concave reflector, which receives the beam coming from the first emitter to give the cut-off beam, a second concave reflector of paraboloid type located in the lower part which, together with the first reflector, provides the unbroken beam from the second emitter, the reflectors being distributed on both sides of two axial planes (P1, P2), including planes inclined under the horizontal plane passing through the optical axis, each reflector having a complex surface with successive sectors extending essentially in the vertical direction, characterized in that: the two reflectors (R1, R2) are designed to be connected by a continuous transition zone (6), the sectors (ZLh1 ... ZLhn, ZLb1 ... ZLbn) of the complex surfaces of the two reflectors are in the extension of each other, in particular a plurality of intersector junctions for the top reflector are in the extension with junctions the bottom reflector - And the passage of a sector (ZLh1) to the neighboring sector (ZLh2) is provided by a fillet (8) removing the sharp corners. Optical module according to claim 1, characterized in that the light source is constituted by a lamp with two filaments (2, 3), each filament constituting a light emitter. Optical module according to claim 1 or 2, characterized in that it is made of pressed sheet metal. Optical module according to claim 1 or 2, characterized in that it is made of thermosetting plastic material injected. Optical module according to any one of the preceding claims, characterized in that the focal length of the lower reflector (R2) is adapted to that of the upper reflector (R1) so that the axial offset between the two reflectors is low. Optical module according to any one of the preceding claims, characterized in that the continuous surface of the transition zone (6) between the upper reflector (R1) and the lower reflector (R2) is defined so as to recover luminous flux for the road beam, facing down, especially to avoid glare. Optical module according to any one of the preceding claims, characterized in that the connection fillet (8) between two adjacent sectors (ZLh1, ZLh2) of complex surface is provided in such a way that any light beam reaching this fillet is reflected for pass below the limit corresponding to the cut of the code beam. Optical module according to one of the preceding claims, characterized in that the radius of the fillet (8) is progressive. Optical module according to one of the preceding claims, characterized in that the sectors (ZLh1, ZLh2) of the upper reflector (R1) are convex towards the front, and the connection fillet (8) is concave forwards. Automotive headlamp incorporating at least one optical module according to one of the preceding claims.

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